HTML::Mason by example

HTML::Mason by example - Presentation Transcript

HTML::Mason by example BPW2007 chrisv.cpan.org Saturday 27 October 2007 1

embed perl in text (and then some) Saturday 27 October 2007 2

“alternatives” • Text::Template & HTML::Template • Template Toolkit • Apache::ASP • Embperl • PHP • ASP (ActiveState ActivePerl) Saturday 27 October 2007 3

building large dynamic websites Saturday 27 October 2007 4

• Amazon • IMDB • del.icio.us • DynDNS • jobs.perl.org • RT Saturday 27 October 2007 5

Apache + mod_perl Apache2 + mod_perl2 Saturday 27 October 2007 6

httpd.conf #PerlModule Apache2::Compat PerlModule HTML::Mason::ApacheHandler <LocationMatch \"\\.html$\"> SetHandler perl-script PerlHandler HTML::Mason::ApacheHandler </LocationMatch> Saturday 27 October 2007 7

preload perl modules startup.pl Saturday 27 October 2007 8

Apache integration (objects) Saturday 27 October 2007 9

by example Saturday 27 October 2007 10

sample “component” % my $planet = \"World\"; Hello, <% $planet %>! Saturday 27 October 2007 11

output Hello, World! Saturday 27 October 2007 12

Greetings, <% (\"Earthlings\", \"Martians\")[rand 2] %> Saturday 27 October 2007 13

in-line perl sections <%perl> my $noun = 'World'; my @time = localtime; </%perl> Hello <% $noun %>, % if ( $time[2] < 12 ) { good morning. % } else { good afternoon. % } Saturday 27 October 2007 14

Mason pushes the boundaries of the term “Templating System” Saturday 27 October 2007 15

“components”: modular design elements Saturday 27 October 2007 16

header.mas <html> <head> <title>Welcome to Wally World!</title> </head> <body bgcolor=\"#CCFFCC\"> Saturday 27 October 2007 17

footer.mas <center><a href=\"/\">Home</ a> </center> </body></html> Saturday 27 October 2007 18

mainpage.html <& header.mas &> this is body text... <& footer.mas &> Saturday 27 October 2007 19

mainpage.html <& header.mas, head => \"Wally World Home\" &> this is body text... <& footer.mas &> Saturday 27 October 2007 20

header.mas <%args> $head </%args> <html> <head> <title><% $head %></title> </head> <body bgcolor=\"#CCFFCC\"> <center><h1><% $head %></h1></center> Saturday 27 October 2007 21

autohandler <html> <head> <title><% $m->base_comp->attr('head') %></title> </head> <body bgcolor=\"#CCFFCC\"> <center> <h1><% $m->base_comp->attr('head') %></h1> </center> % $m->call_next; <center><a href=\"/\">Home</a></center> </body></html> Saturday 27 October 2007 22

mainpage.html <%attr> head => \"Wally World Home\" </%attr> this is body text... Saturday 27 October 2007 23

dhandlers e.g. http://myserver/newsfeeds/LocalNews/Story1 /newsfeeds/LocalNews/Story1 => no such thing /newsfeeds/LocalNews/dhandler => no such thing /newsfeeds/dhandler => found! (search ends) /dhandler (The found dhandler would read “LocalNews/Story1” from $m->dhandler_arg and use it as a retrieval key into a database of stories) Saturday 27 October 2007 24

components ~ subs <%init> my $ua = $r->header_in('User-Agent'); return ($ua =~ /Mozilla/i && $ua !~ /MSIE/i) ? 1 : 0; </%init> Saturday 27 October 2007 25

dhandlers vs autohandlers • use an autohandler when you have a set of components to handle your pages and you want to augment them with a template/ﬁlter • use a dhandler when you want to create a set of “virtual URLs” that don't correspond to any actual components, or to provide default behavior for a directory Saturday 27 October 2007 26

Mason Request Objects Two global per-request objects are available to all components: $r (provides a Perl API to current Apache request) and $m (provides a Perl API to current Mason request) $r->uri # the HTTP request URI $r->content_type # set or retrieve content-type $m->caller() # returns the calling component $m->dhandler_arg() # returns url parts $m->redirect(URL, [HTTP status]) Saturday 27 October 2007 27

http://masonhq.com/ Saturday 27 October 2007 28

http://masonbook.com/ Saturday 27 October 2007 29

thank you Saturday 27 October 2007 30